Expansible drill



Sept. 3, 1935. s VANDERUCK 2,013,257

EXPANS IBLE DRILL Filed Feb. '7, 1935 2 Sheets-Sheet l A9 i 6 Z a. /5 gV j 4 7 U I nventm- Sept. 3, 1935. s. VANDERLICK 2,013,257

I EXPANSIBLE DRILL Filed Feb. 7, 1935 2 Sheets-Sheet 2 T 6. Inventor Z175fanl z lizdfrlz'alk Patented Sept. 3, 1935 EXPANSIBLE DRILL StanleyVanderlick, Nanticoke, Pa.

Application February 7, 1935,.Serial. No. 5,451

3 Claims.

a drill of the character above mentioned espeoially adapted forenlarging the bore of a previously drilled hole, to provide at the innerend of the bore a space for an explosive, as is done in;

for example, coal mining operations.

A further object of the invention is to provide a drill of thischaracter which is characterized by extreme simplicity and economy inconstruction and number of parts.

The invention together with its objects and advantages will be bestunderstood from a study of the following description taken in connectionwith the accompanying drawings wherein:

Figure 1 is a view illustrating a bore completed with my improved drill.

Figure 2 is a detail .elevational view illustrating the application ofthe invention.

Figure 3 is a detail sectional view of the expansible drill.

Figure 4 is an elevational view of a rod forming part of the invention.

Figure 5 is a perspective view of a blade.

Figure 6 is a sectional view taken substantially on the line 6-6 ofFigure 5.

Figure 7 is an end elevational view of a tubular member.

Figure 8 is an elevational view of a collar.

Figure 9 is an end elevational view of a collar.

Figure 10 is an elevational view of a pilot bit.

My improved expansible bit comprises a body bar I having at one end alongitudinal slot 2. Secured tothe bar I by a pin 3 or in any othersuitable manner, at the end of the bar remote from the slot 2 is acollar 4. The collar 4 is provided with notches 5 in which are pivotedas at 6 one end of blades 7. These blades are substantially wedge shapedin cross section as shown in Figure 6 and their free ends are curvedoutwardly as at la.

A tubular member 8 slidably receives the slotted end 2 of the bar I andis provided at one end with a pin 9 that operates in the slot 2. At thepin equipped end thereof the sleeve 8 is provided with a collar Iil thatis provided in its outer edge with dove-tail slots II that receive theblades I which latter are as previously referred to, substantiallydove-tail in cross section.

The sleeve 8 is adapted to receive therein the shank I2a of aconventional pilot bit I Z, the shank being secured in the sleeve 8through the medium of a cotter pin or the like I3.

In actual practice, a bore I8 of the proper length and diameter is firstdrilled with the usual drilling apparatus. Such apparatus usuallyincludes, in addition to the usual drill head, a supporting post I4driven into the ground as shown. On the upper end of the supporting postis a threaded sleeve I5 on which is threaded a rod l6 equipped at oneend with a handle I'I. At its opposite end the rod or screw I6 isprovided to accommodate the usual drill bit, (not shown) 0 After thebore I8 has been drilled, the usual bit is removed and my improvedexpansible bit is substituted therefor. In substituting my bit the freeend of the shank I is secured within one end of a connecting bar orsleeve I9 which sleeve 15 is square in cross section, and the free endof the shank or bar I is provided with a recess Ia to receive the springpressed locking ball or other element with which the end of theconnecting sleeve I9 is equipped. The sleeve I9 is connected 20 at itsother end to the squared non-threaded end of the rod I6 in substantiallythe same manner.

With my improved bit assembly thus connected to the rod I6, the rod isrotated for moving the assembly lengthwise of the bore I8 to the inner25 end of the bore when the pilot bit I2 begins its drilling operationfollowed by the expansible bit carrying the blades I'I. During thisdrilling operation, the shank I moves inwardly of the sleeve 8 againstthe action of a coil spring 20 disposed 30 about the shank I between thecollars 4 and I0 as shown in Figure 3, with the result that myexpansible bit expands, that is to say, the arms or blades "I are causedto move radially outwardly with the result that a substantially conicalbore I8a first results and after the widest end of the bore I8a is madefurther drilling operation will result in the provision of an extensionbore IBb of substantially the same diameter as the widest or largestdiameter of the tapered bore I 8a. Thus with this expansible bit anenlarged bore or pocket is provided at the inner end of the usual borel8, and into this pocket formed by the bores I8a and I8b the explosiveis packed.

It has been found in actual practice, that better results are obtainedby the provision of bores such as the connecting bores I8a and lb forreceiving the powder than where the powder is packed into a bore similarto bore I8 and of uniform diameter throughout its entire length.

Among the advantages of the invention are: better grade ofcoal-elimination of pot-holes by confining explosives into pocket;greatly reduce explosive expenses; saving of time and labor, (reducingnumbers of holes) and; elimination of fire hazards as now fromunexploded powder left in burning holes.

Having thus described the invention, what is claimed as new is:

1. An expansible drill bit including a shank, a sleeve slidablyreceiving the shank, a collar on one end of the sleeve, a collar on theshank, blades pivoted at one end to the collar on the shank, and thecollar on the sleeve being provided with mortise notches, and saidblades being of a cross sectional shape corresponding to said notchesand engaging in said notches, and a spring disposed about said shankbetween said collars.

2. An expansible drill bit including a shank, a sleeve slidablyreceiving the shank, a collar on one end of the sleeve, a collar on theshank,

blades pivoted at one end to the collar on the shank, the collar on thesleeve being provided with mortise notches, said blades being of a crosssectional shape corresponding to said notches and engaging in saidnotches, a spring disposed about said shank between said collars, and apilot bit having a shank secured within said sleeve.

3. An expansible drill bit including a shank, a sleeve slidablyreceiving the shank, a collar on one end of the sleeve, a collar on theshank, blades pivoted at one end to the collar on the shank, the collaron the sleeve being provided with mortise notches, said blades being ofa cross sectional shape corresponding to said notches and engaging insaid notches, a spring disposed about said shank between said collars, apilot bit having a. shank secured within said sleeve, an operatingscrew, and means detachably connecting the free end of said shank withsaid screw.

STANLEY VANDERLICK.

